Fuel Water Separator Filter

ABSTRACT

A fuel water separator filter that is configured as a filter-in-filter construction with multiple water separating layers to separate water from the fuel. The fuel water separator filter is configured for use on a suction side of a fuel pump, and includes a neck with a radially outward facing seal that in use seals with the filter housing. The filter housing is formed with an isolated water sump that in use is isolated from water that is stripped from the fuel by the first stage of the outer filter.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 62/128,708, filed on Mar. 5, 2015, the entirety of whichis incorporated herein by reference.

FIELD

Embodiments of this disclosure relate generally to a fuel waterseparator filter.

BACKGROUND

Fuel water separator filters that filter fuel, for example diesel fuel,and also separate water from the fuel before the fuel is passed to theengine are known. Various fuel water separator filter constructions aredescribed in, for example, U.S. Pat. Nos. 7,857,974 and 7,935,255.Conventional fuel water separator filters are generally disposed on thehigh pressure, or downstream, side of a fuel pump. A number of such fuelwater separator filters typically employ an outer diameter seal thatseals with an interior surface of a filter housing. Additionally, invarious conventional fuel water separator filter designs, an outerdiameter of a bottom endplate of the fuel water separator filtertypically seals with the interior of the filter housing to form a watersump.

SUMMARY

Embodiments provided herein relate generally to a fuel water separatorfilter system. More specifically, the embodiments relate to a fuel waterseparator filter that is configured as a filter-in-filter constructionwith multiple water separating layers to separate water from the fuel.

In one embodiment, the fuel water separator filter is configured for useon a suction, or low pressure, side of a fuel pump, as opposed to beingdisposed on the high pressure, or downstream, side of a fuel pump. Insome alternative embodiments, the described fuel water separator filtermay be disposed on the high pressure side of a fuel pump.

In another embodiment, a suction side fuel water separator filterincludes an outer filter and an inner filter disposed within and spacedapart from the outer filter. The outer filter may include a pleatedfilter media layer and a coalescing layer on an inner surface of thepleated filter media layer. The inner filter may include at least one ofa pleated filter or a hydrophobic screen filter for additional waterseparation, and may include a structure that attaches the inner filterto the outer filter.

In another embodiment, a fuel water separator filter is provided thatincludes an inner filter with at least three sealing regions. Thesealing regions are configured to produce a seal between the innerfilter and a filter housing, a standpipe structure, and an endplate ofan outer filter. The inner filter may be attached to the outer filterthrough snap-lock attachments, and may include an anti-backoff portionconfigured to prevent the inner filter from disengaging the outerfilter. The inner filter may include openings configured to allow waterremoved from the fuel to drain to a water sump of the filter housing.

In another embodiment, a fuel water separator filter is provided thatincludes an inner filter formed integrally as a single unitary structurewith an endplate of an outer filter. The inner filter may include asealing region configured to seal against a standpipe structure and asealing region configured to seal against a filter housing. The innerfilter may include openings configured to allow water removed from thefuel to drain to a water sump of the filter housing.

In another embodiment, a fuel water separator filter is provided thatincludes a multipart inner filter configured to snap-lock engage anouter filter. The inner filter may include a frame structure, asnap-lock structure and a top cover, each of which may be formedindependently or together as a unitary structure. The snap-lock portionincludes a sealing region configured to seal against a standpipestructure and snap-lock legs configured to engage a base portion. Thesnap-lock legs form openings configured to allow water removed from thefuel to drain to a water sump of a filter housing, and may alsoself-center the inner filter in the outer filter. The base portion maybe formed as part of an endplate of the outer filter, or may be formedas a separate piece that snap-lock engages with the endplate of theouter filter. The base portion may include a sealing region configuredto seal against the filter housing.

In another embodiment, a fuel water separator filter is provided thatincludes an outer filter, an inner filter at least partially disposedwithin and secured to the outer filter, a first endplate configured toseal a first end of the outer filter, and a second endplate configuredto seal a second end of the outer filter. The outer filter and the innerfilter combined provide a plurality of water separating layers. Theinner filter includes a first sealing region configured to produce aseal between the inner filter and a standpipe structure of a filterhousing, and openings configured to allow water separated from a fuelflow through the fuel water separator filter to flow to an isolatedwater sump of the filter housing.

The second endplate may be a part of the outer filter and the innerfilter may include a snap-lock attachment configured to engage the outerfilter. The inner filter may include an anti-backoff portion configuredto engage the outer filter and prevent the inner filter from disengagingthe outer filter. The inner filter may include a second sealing regionconfigured to produce a seal between the inner filter and a portion ofthe filter housing other than the standpipe structure and a thirdsealing region configured to produce a seal between the inner filter andthe second endplate. The second endplate may be a part of the innerfilter. The inner filter may be formed integrally as a single unitarystructure with the second endplate. The inner filter may include asecond sealing region configured to seal against the filter housing. Theinner filter may include a frame structure, a snap-lock structureconfigured to engage the outer filter, and a top cover. The snap-lockstructure and the frame structure may be formed as separate components.The snap-lock structure and the frame structure may be integrally formedas single unitary structure. The frame structure and the top cover maybe formed as separate components. The snap-lock structure may includethe first sealing region. The snap-lock structure may include snap-locklegs configured to engage a base portion. The snap-lock legs may beconfigured to self-center the inner filter in the outer filter. The baseportion may be integrally formed as a single unitary structure with thesecond endplate. The base portion may be formed as a separate piece thatsnap-lock engages with the second endplate. The base portion may includea second sealing region configured to produce a seal between the innerfilter and a portion of the filter housing other than the standpipestructure.

In another embodiment, a fuel water separator system is provided thatincludes a filter housing and a fuel water separator filter disposed inthe filter housing. The filter housing including a fuel inlet, a fueloutlet, a standpipe structure, and an isolated water sump. The fuelwater separator filter including an outer filter, an inner filter atleast partially disposed within and secured to the outer filter, a firstendplate configured to seal a first end of the outer filter, and asecond endplate configured to seal a second end of the outer filter. Theouter filter and the inner filter combined providing a plurality ofwater separating layers. The inner filter includes a first sealingregion configured to produce a seal between the inner filter and thestandpipe structure, and openings configured to allow water separatedfrom a fuel flow through the fuel water separator filter to flow to theisolated water sump.

The fuel water separator system may include a fuel pump in fluidcommunication with the fuel water separator filter. The fuel waterseparator system may be disposed on a low pressure side of the fuel pumpor on a high pressure side of the fuel pump. The filter housing mayinclude a wall configured to separate an interior space of the filterhousing into the isolated water sump and a filter chamber configured toreceive the fuel water separator filter. The inner filter may include asecond sealing region configured to produce a seal between the innerfilter and a portion of the filter housing other than the standpipestructure, and a third sealing region configured to produce a sealbetween the inner filter and the second endplate. The second endplatemay be a part of the inner filter. The inner filter may include a framestructure, a snap-lock structure configured to engage the outer filter,and a top cover.

In another embodiment, a fuel water separator filter is provided thatincludes an outer filter and an inner filter at least partially disposedwithin and secured to the outer filter. The outer filter and the innerfilter combined provide a plurality of water separating layers. Theinner filter includes means for securing the inner filter to the outerfilter and means for producing a seal between the inner filter and astandpipe structure of a filter housing. The fuel water separator filtermay additionally include means for preventing the inner filter fromdisengaging the outer filter. The fuel water separator filter mayadditionally include means for allowing water separated from a fuel flowthrough the fuel water separator filter to an isolated water sump of thefilter housing.

BRIEF DESCRIPTION OF THE DRAWINGS

References are made to the accompanying drawings that form a part ofthis disclosure, and which illustrate the embodiments in which thesystems and methods described in this Specification can be practiced.Like reference numbers represent like parts throughout the drawings.

FIG. 1 is a cross-sectional view of a fuel water separator filterinstalled in a filter housing.

FIG. 2 is a cross-sectional view of a fuel water separator filter,according to one embodiment.

FIG. 3 is a cross-sectional view of an outer filter of the embodiment ofFIG. 2.

FIG. 4 is a cross-sectional view of an inner filter of the embodiment ofFIG. 2.

FIG. 5 is a detailed cross-sectional view of a snap-lock featureattaching the outer filter of FIG. 3 and the inner filter of FIG. 4.

FIG. 6 is a cross-sectional view of the fuel water separator of FIG. 2engaged with a standpipe structure.

FIG. 7 is a perspective view of the standpipe structure shown in FIG. 6.

FIG. 8 is a cross-sectional view of a fuel water separator filter,according to another embodiment.

FIG. 9 is a cross-sectional view of an inner filter of the embodiment ofFIG. 8.

FIG. 10 is a perspective view of the inner filter of the embodiment ofFIG. 8.

FIG. 11 is a cross-sectional view of a fuel water separator, accordingto another embodiment.

FIG. 12 is a cross-sectional view of the outer filter of the embodimentof FIG. 11.

FIG. 13 is a cross-sectional view of an upper portion of the innerfilter of the embodiment of FIG. 11.

FIG. 14 is a cross-sectional view of the inner filter of the embodimentof FIG. 11.

FIG. 15 is an exploded perspective view of the inner filter of theembodiment of FIG. 11.

FIG. 16 is a perspective view of an endplate of the embodiment of FIG.11.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

Embodiments provided herein relate generally to a fuel water separatorfilter system. More specifically, the embodiments relate to a fuel waterseparator filter that is configured as a filter-in-filter constructionwith multiple water separating layers to separate water from the fuel.

In one embodiment, the fuel water separator filter is configured for useon a suction, or low pressure, side of a fuel pump, as opposed to beingdisposed on the high pressure side. In some embodiments, the describedfuel water separator filter may be disposed on the high pressure side ofa fuel pump.

The fuel water separator filter is configured to be housed in a filterhousing that is formed with an isolated water sump. The water sump isconfigured to be isolated from water that is stripped from the fuel bythe first stage of the water separating layers. The isolated water sumpis formed in the filter housing separate from the filter, i.e. thefilter does not contribute to forming the isolated water sump, and theincoming fuel is separated from the water sump. The filter housing maybe pre-formed with the isolated water sump, or an existing filterhousing may be modified to create the isolated water sump.

With reference now to FIG. 1, a filter assembly 10 is illustrated thatincludes a fuel water separator filter 12 disposed within a filterhousing 14. The housing 14 includes an inlet 16 through which fuelcontaminated with water may enter, and an outlet 18 through whichfiltered fuel with water removed may flow downstream, such as to anengine. When used on the suction side, the outlet 18 is connected to afuel pump (not shown) which pumps the fuel, such as to the engine.

The housing 14 defines an isolated water sump 20 at the base thereofthat is configured to collect water that is separated from the fuel bythe filter 12. A drain port 22 is provided that permits draining ofwater from the water sump 20. The isolated water sump 20 is formed by awall 24 that is disposed within the housing 14, and that separates theinterior space of the housing 14 into the water sump 20 and an upperfilter chamber 26 that receives the filter 12.

The filter 12 may be provided with at least three water separatinglayers. In the example shown in FIG. 1, three water separating layersare provided, with a first water separating layer formed by a filtrationmedia 30, a second water separating layer formed by a coalescing layer32, and a third water separating layer formed by a hydrophobic screenlayer 34.

With reference to FIG. 1 and the flow paths shown therein, the incomingfuel enters the filter chamber 26 which is separated from the water sump20 along the incoming fuel flow path 40. The fuel flows into an areaoutside the filter 12 and the water sump 20, and then into thefiltration media 30 as shown by the unfiltered fuel flow path 42. Waterthat is stripped from the fuel by the filtration media 30 sinks to thebase of the filter chamber 26 outside of the filter. The fuel passesthrough the filtration media 30 and then to the coalescing layer 32which coalesces water within the fuel to form large water droplets 44that sink to the base of the filter 12 and through suitable passagewaysin the wall 24 into the water sump 20 as shown by the water droplet flowpath 46. The fuel then flows through the hydrophobic screen layer 34 asshown by the intermediate fuel flow path 48 and any additional waterdroplets in the fuel are stripped out by the hydrophobic screen layer 34and sink down into the water sump 20. The filtered fuel then flows intoa standpipe structure of the filter housing 14 which forms part of theoutlet 18 along the filtered fuel flow path 50. The outer filter mayseal against a wall of the water sump to prevent unfiltered fuel andwater from bypassing the filter 12.

The water that is stripped from the fuel by the filtration media 30 mayflow into the water sump 20 during filter service. For example, duringservicing, when the filter 12 is removed from the filter housing, thewater separated by the filtration media 30 may drain through thepassageways in the wall 24 and into the water sump 20.

The filter housing 14 may include an upper housing and a lower housingthat are detachably connected together and sealed to one another at aconnection point. The upper housing and the lower housing may bedetachably connected to one another using any suitable attachmentmechanism, for example a clamp mechanism, bolts, or any other mechanismknown in the art. The lower housing may include both the inlet 16 andthe outlet 18.

The filter housing may be pre-formed with the isolated water sump 20, oran existing filter housing may be modified to create the isolated watersump 20. The isolated water sump 20 may be formed in the lower housingby modifying an existing lower housing. In particular, the wall 24 maybe a structure that is installed within the lower housing to create thewater sump 20. The wall 24 may be a generally plate-like structure withan outer perimeter edge that generally matches the interior surface ofthe lower housing beneath the fuel inlet 16. A sealing gasket may bedisposed on the outer perimeter edge of the wall 24 to seal with theinterior surface of the housing to prevent fuel leakage between theperimeter edge and the housing.

The wall 24 also includes a central opening to accommodate a standpipeor fuel flow. A plurality of openings or passageways may be formedthrough the wall 24 to allow water to flow through the wall and into thewater sump 20.

Optionally, a standpipe structure may be secured to a fuel outletstructure of the housing 14 to form a continuation of the outlet 18. Thestandpipe structure may be secured to an upwardly extending post formedin the lower housing 14. The standpipe structure may include a bottomend portion that is secured to the post, for example by fitting into thepost and being secured to the post in any suitable manner, such as usingthreads, friction, an adhesive, or thermal bonding. An upper portion ofthe standpipe may extend upwardly into the inner filter when the filter12 is installed (as shown in FIG. 1). In use, fuel that has beenfiltered by the filter 12 may enter the upper portion of the standpipestructure through one or more inlet passages formed in the upperportion, for example in the side or at the top end thereof, and thencontinue on through the outlet 18.

In one embodiment, the standpipe structure may be provided with a valvemechanism that forms part of a no filter, no run system. The valvemechanism may be designed to control flow into and/or through thestandpipe structure and the remainder of the outlet 18, with the valvemechanism being located so as to be engaged by a valve actuating portionof the filter 12, when the filter 12 is installed in the filter housing14. When a filter with the correct valve actuating portion is installed,the valve mechanism permits fuel flow into and through the standpipestructure. When no filter is installed, or when an incorrect filterhaving no valve actuating portion or having an incorrect valve actuatingportion is installed, the valve mechanism prevents all fuel flow throughthe standpipe structure or limits the fuel flow to an amountinsufficient to permit engine operation. Any valve mechanism that isconfigured to achieve these functions may be utilized.

The filter 12 is configured as a filter-in-filter construction with anouter filter and an inner filter. The inner filter is designed to fitwithin the outer filter and connect thereto such that the outer andinner filters are secured to one another. In one embodiment, thefilter-in-filter may be configured such that the outer and inner filtersare configured in a concentric arrangement. The outer and inner filtersmay have any appropriate shape, such as a cylindrical shape.

The outer filter includes the filtration media 30 which may be anyfiltration media that is suitable for filtering the fuel by removingparticulate contaminants. In one example, the filtration media 30 mayinclude pleated paper filtration media. The filtration media 30 may bearranged into a closed configuration or ring having a first end and asecond end and circumscribing a central cavity having a longitudinalaxis. The filtration media 30 may have any suitable cross-sectionalshape defining the central cavity, such as circular, triangular, oval,or the like.

An embodiment of the filter is depicted in FIGS. 2-7. The filter 112includes an outer filter 160 and an inner filter 162. The outer filterincludes filtration media 130. A first endplate 178 is sealinglyattached to the first end 172 of the filtration media 130 to close thefirst end 172 of the filtration media 130, and a second endplate 180 issealingly attached to the second end 174 of the filtration media 130 toclose the second end 174 of the filtration media. A coalescing layer 132is secured to the interior side of the media 130 and extends from thefirst endplate 178 to the second endplate 180. A centertube 190 issecured to the interior of the coalescing layer 132 and extendssubstantially from the first endplate 178 to the second endplate 180 tohelp support the inner diameter of the media 130 and prevent it fromcollapsing. The centertube 190 may include perforation openings 194configured to allow the passage of fuel therethrough. In addition, anoptional half outer wrap, the construction of which is known, may bedisposed around the outer circumference of the filtration media 130.

The first endplate 178 is generally constructed without fluid flowpassageways, such that there is no fuel flow through the first endplate178. However, an optional air vent 186 may be provided in the firstendplate 178 to allow venting of air from the interior of the outerfilter 160.

The second endplate 180 includes a central opening formed therein, and aneck 188 surrounding the opening and extending upwardly from theendplate 180 into the central cavity of the filter. The neck 188 is acircumferentially continuous structure configured to engage the innerfilter 162 when the inner filter 162 is installed in the outer filter160 through the central opening of the endplate 180. As shown in FIG. 2,the inner filter 162 is spaced radially inward from the centertube 190and the coalescing layer 132, producing a gap. The neck 188 of thesecond endplate 180 is radially positioned so as to be disposed withinthe gap.

The centertube 190 may include an anti-backoff element, such as ananti-backoff protrusion 192. The anti-backoff protrusion may extend intothe central cavity of the outer filter 160, for example the anti-backoffprotrusion 192 may extend in a direction substantially orthogonal to aninterior surface of the centertube 190, and may be in the form of a ribextending radially inward from the surface of the centertube 190. Theanti-backoff protrusion 192 is configured to engage the inner filter 162and prevent the inner filter 162 from backing out of the outer filter160 when the filters are combined. As shown in FIG. 4, the portion ofthe inner filter 162 that engages the anti-backoff protrusion 192 may bea snap-fit prong 142. The anti-backoff protrusion 192 and correspondingsnap-fit prong 142 may be a means for preventing the inner filter 162from disengaging the outer filter 160.

The inner filter 162 may include a frame structure 140. The snap-fitprong 142 may be located on the frame structure 140, and may be formedas a unitary structure therewith. The frame structure 140 may include asealing surface 146 configured to seal against a sealing surface 156 ofa standpipe structure 150. The sealing surface 146 may include one ormore seals, such as elastomeric seals or o-rings. Alternatively, thesealing surface 146 may include a plurality of projections formedintegrally with the frame structure 140 and configured to seal againstthe sealing surface 156 of the standpipe structure 150. Openings 144 maybe formed in the frame structure 140, such that water separated from thefuel by the filter may flow to a water sump. The frame structure 140includes an open end 152, configured to accept the standpipe structure150 and to allow water to flow to the water sump. A seal 114 is providedon an exterior of the frame structure 140 at the open end 152 to sealthe frame structure against a surface of the filter housing. The seal114 may be an o-ring, and may be disposed in a seal locating structure,such as a channel, formed on the frame structure 140.

A filter media 134 is supported by the frame structure 140 and disposedover the openings therein. The filter media 134 may be configured toseparate remaining water and/or particulate matter from the fuel beforeit passes in to the center cavity of the inner filter 162. The filtermedia 134 may be a hydrophobic screen configured to prevent the passageof water present in the fuel therethrough.

The frame structure 140 may also include a collar 147 configured tocontact the second endplate 180 when the inner filter 162 is installedin the outer filter 160. The collar 147 may extend in a directionsubstantially orthogonal to the longitudinal axis of the frame structure140, and have a diameter that exceeds the diameter of the centralopening of the second endplate 180. The collar 147 is configured toprevent the over insertion of the inner filter 162 and enhance a sealbetween the frame structure 140 and the second endplate 180.

The frame structure 140 may be formed from any suitable material by anysuitable process. A molding process, such as an injection moldingprocess, may be employed to form the frame structure 140. The framestructure 140 may be formed in two or more pieces, which are laterattached together. For example, a base portion of the frame structurewhich includes the collar may be attached to a molded upper portion thatincludes the filter media by any suitable attachment method.

The inner filter 162 may include three separate seals: the sealingsurface 146 which seals against the standpipe structure, the seal 114which seals against the filter housing, and sealing projections 148which seal against the second endplate 180. Including all of the sealson the inner filter 162 simplifies the production of the filter. Forexample, the first endplate 178 and second endplate 180 may be producedfrom relatively inexpensive materials, such as metal or plastisol, onexisting production equipment, while the inner filter 162 is formed frommaterials, such as plastic or epoxy, and by methods that facilitate theformation of effective seals. In this way, the cost of producing thefilter may be reduced. Additionally, the snap-lock features of the innerfilter 162 and the outer filter 160 allow for a simplified filterassembly process that does not require additional gaskets or glue, andprevents the disengagement of the inner filter 162 from the outer filter160.

The frame structure 140 also includes a snap-lock projection 143 and thesealing projections 148, each of which is configured to engage the neck188 of the second endplate 180. The neck 188 may have a diameter thattapers towards the interior of the inner filter 162. In other words, thediameter of the neck 188 at the free end may be less than the diameterof the neck 188 at the point of attachment to the second endplate 180.The geometry of the neck 188 allows the snap-lock projection 143 toprevent the removal of the inner filter 162 after installation in theouter filter 160. As shown in FIG. 5, the free end of the neck 188 islocated radially inward of the snap-lock projection 143 when the innerfilter 162 is fully installed in the outer filter 160, and the free endof the neck 188 is prevented from passing over the snap-lock projection143. For example, the snap-lock projection may have a face adjacent tothe free end of the neck 188 when the inner filter 162 is installed thatextends substantially orthogonal to the longitudinal axis of the framestructure 140.

The sealing projections 148 of the frame structure 140 are configuredsuch that the neck 188 bears against the sealing projections 148 withsufficient force to produce a seal that prevents undesired fluid flowbetween the frame structure 140 and the neck 188. The sealingprojections 148 may extend from the frame structure 140 to an extentthat sufficient contact is produced with the neck 188 while alsoallowing the free end of the neck 188 to engage the snap-lock projection143. The frame structure may include any appropriate number of sealingprojections 148, such as two sealing projections. A plurality of sealingprojections 148 may be provided where each sealing projection extendsfrom the frame structure to a lesser height than the sealing projectionsdisposed closer to the collar 147. Such a configuration may ensure thateach sealing projection 148 is in contact with the neck 188 when theinner filter 162 is installed in the outer filter 160.

As shown in FIGS. 6 and 7, the standpipe structure 150 may include afuel outlet passage 158 in fluid communication with the central cavityof the inner filter 162. When the filter is properly engaged with thestandpipe structure 150, the fuel outlet passage 158 receives fuel onlyfrom the central cavity of the inner filter 162. In other words, thefuel that enters the fuel outlet passage 158 has passed through theouter filter 160 and the inner filter 162. The seal produced between thesealing surface 156 of the standpipe structure 150 and the sealingsurface 146 of the frame structure 140 prevents fluid from entering thecentral cavity of the inner filter 162, and thereby the fuel outletpassage 158, without passing through the inner filter 162. The sealingsurface 156 of the standpipe structure 150 may extend along a directionoblique to the longitudinal axis of the filter, such that the sealingsurface 156 of the standpipe structure 150 engages the sealing surface146 of the frame structure 140 while accommodating slight misalignmentsor differences due to manufacturing tolerances. According to anotherembodiment, the sealing surface of the standpipe structure may belocated on an inner diameter of the standpipe structure.

Another embodiment of the filter 212 is shown in FIGS. 8-10. The filterincludes an outer filter 260 and an inner filter 262.

The outer filter includes filtration media 230. A first endplate 278 issealingly attached to the first end 272 of the filtration media 230 toclose the first end 272 of the filtration media 230. A second endplate280 is part of the inner filter 262 and is sealingly attached to thesecond end 274 of the filtration media 230 to close the second end 274of the filtration media 230. A coalescing layer 232 is secured to theinterior side of the filtration media 230 and extends from the firstendplate 278 to the second endplate 280. A centertube 290 is secured tothe interior of the coalescing layer 232 and extends substantially fromthe first endplate 278 to the second endplate 280 to help support theinner diameter of the filtration media 230 and prevent it fromcollapsing. The centertube 290 may include perforation openings to allowthe passage of fuel therethrough. In addition, an optional half outerwrap, the construction of which is known, may be disposed around theouter circumference of the media 230.

The first endplate 278 is generally constructed without fluid flowpassageways, such that there is no fuel flow through the first endplate278. However, if deemed appropriate, an optional air vent 286 may beprovided in the first endplate 278 to allow venting of air from theinterior of the outer filter 260.

The second endplate 280 may be formed integrally with the framestructure 240 of the inner filter 262 as a single unitary element. Thesecond endplate 280 includes a central opening 252 that is configured toaccept a standpipe structure. As shown in FIG. 8, the inner filter 262is spaced radially inward from the centertube 290 and the coalescinglayer 232, producing a gap.

The frame structure 240 may include a sealing surface 246 configured toseal against a sealing surface of a standpipe structure. The sealingsurface 246 may include one or more seals, such as elastomeric seals oro-rings. Alternatively, the sealing surface 246 may include a pluralityof projections formed integrally with the frame structure 240 andconfigured to contact the sealing surface of the standpipe structure.Openings 244 may be faulted in the frame structure 240, such that waterseparated from the fuel by the filter may flow to a water sump. Theframe structure 240 includes a central opening 252, configured to acceptthe standpipe structure. A seal 214 is provided on an exterior of theframe structure 240 proximate the central opening 252 to seal the framestructure against a surface of the filter housing. The seal 214 may bean o-ring, and may be disposed in a seal locating structure, such as achannel, formed on the frame structure 240. The seal 214 may be formedon a portion of the frame structure 240 that extends beyond the secondendplate 280 in a direction away from the interior of the filter.

A filter media 234 is supported by the frame structure 240 and disposedover openings therein. The filter media 234 may be configured toseparate remaining water and/or particulate matter from the fuel beforeit passes in to the center of the inner filter 262. The filter media 234may be a hydrophobic screen configured to prevent the passage of waterpresent in the fuel therethrough.

The frame structure 240 and the second endplate 280 may be formed fromany suitable material by any suitable process. A molding process, suchas an injection molding process may be employed to form the framestructure 240 and the second endplate 280 as a single unitary structure.

The inner filter 262 may include two separate seals: the sealing surface246 which seals against the standpipe structure, and the seal 214 whichseals against the filter housing. Including all of the sealing surfaceson the inner filter 162 simplifies the production of the filter.Additionally, forming the second endplate 280 and the frame structure240 as a single element reduces the number of parts in the filter, andeliminates a sealing junction between the second endplate 280 and theframe structure 240. In this way, the cost of producing the filter maybe reduced. The second endplate 280 may be sealingly attached to thefiltration media 230 of the outer filter 260 by an adhesive, such asglue.

Another embodiment of the filter 312 is shown in FIGS. 11-16. The filterincludes an outer filter 360 and an inner filter 362.

The outer filter 360 includes filtration media 330. A first endplate 378is sealingly attached to the first end 372 of the filtration media 330to close the first end 372 of the filtration media 330. A secondendplate 380 is sealingly attached to the second end 374 of thefiltration media 330 to close the second end 374 of the filtration media330. A coalescing layer 332 is secured to the interior side of thefiltration media 330 and extends from the first endplate 378 to thesecond endplate 380. A centertube 390 is secured to the interior of thecoalescing layer 332 and extends substantially from the first endplate378 to the second endplate 380 to help support the inner diameter of thefiltration media 330 and prevent it from collapsing. The centertube 390may include perforation openings 394 to allow the passage of fueltherethrough. In addition, an optional half outer wrap 336, theconstruction of which is known, may be disposed around the outercircumference of the filtration media 330.

The first endplate 378 is generally constructed without fluid flowpassageways, such that there is no fuel flow through the first endplate378. However, if deemed appropriate, an optional air vent 386 may beprovided in the first endplate 378 to allow venting of air from theinterior of the outer filter 360.

The second endplate 380 includes a central opening 352 formed therein. Aneck 388 extends upwardly from the endplate 380 into the central cavityof the filter. The neck 388 is a circumferentially continuous structurethat is configured to engage the inner filter 362. As shown in FIG. 11,the inner filter 362 is spaced radially inward from the centertube 390and the coalescing layer 332, producing a gap. The neck 388 is radiallypositioned so as to be disposed within the gap.

The inner filter 362 may include a frame structure 340, a top cover 342and a snap-lock structure 344. The snap-lock structure 344 may include aseal 346 configured to seal against a standpipe structure. The seal 346may be an elastomeric seal, and may include an opening 354 configured toaccept the standpipe structure. Openings may be formed in the snap-lockstructure 344 between the snap-lock legs 345, such that water separatedfrom the fuel by the filter may flow to a water sump. As shown in FIG.14, the snap-lock legs are configured to engage the neck 388, andself-center the inner filter 362 with respect to the outer filter 360.

The neck 388 may be formed as a part of the second endplate 380 whichincludes a central opening 352 configured to accept the standpipestructure. Alternatively, the neck 388 may be formed as part of a baseportion 382. The base portion may include snap-lock tabs 383 configuredto engage the second end plate 380 when the filter is assembled. A seal314 is provided on an exterior of the filter proximate the centralopening 352 to seal the filter against a surface of the filter housing.The seal 314 may be an o-ring, and may be disposed in a seal locatingstructure, such as a channel, and may be provided on the base portion382 or the second endplate 380.

A filter media 334 is supported by the frame structure 340 and disposedover openings therein. The filter media 334 may be configured toseparate remaining water and/or particulate matter from the fuel beforeit passes in to the center of the inner filter 362. The filter media 334may be a hydrophobic screen configured to prevent the passage of waterpresent in the fuel therethrough.

The frame structure 340 may be formed from any suitable material by anysuitable process. A molding process, such as an injection moldingprocess, may be employed to form the frame structure 340. The framestructure 340 may be formed integrally with the snap-lock structure 344and/or the top cover 342. Alternatively, the frame structure 340 may beformed separately from the snap-lock structure and/or the top cover 342.

The snap-lock structure 344 may be formed as separate element from theframe structure 340. The snap-lock structure 344 may include a channel347 configured to engage the frame structure. The channel 347 of thesnap-lock structure 344 may be configured such that fluid is preventedfrom flowing between the frame structure 340 and the snap-lock structure344 when the inner filter 362 is installed in the outer filter 360.

The top cover 342 of the inner filter element 3632 may include a varietyof protrusions configured to locate the top cover 342 with respect tothe first endplate 378. As shown in FIG. 15, the top cover 342 mayinclude tabs configured to engage the frame structure 340, andprojections configured to locate the top cover 342 with respect to thefirst endplate 378. The top cover 342 may include a channel configuredto accept the frame structure 340, or may include a projection extendingin the direction of the central cavity of the filter configured tocontact the inner surface of the frame structure. The manner in whichthe top cover 342 engages the frame structure 340 prevents fluid fromflowing between the frame structure 340 and the top cover 342.

The first endplate 378 and second endplate 380 may be produced fromrelatively inexpensive materials, such as metal or plastisol, onexisting production equipment, while the inner filter 162 may be formedfrom materials, such as plastic or epoxy, and by methods that facilitatethe formation of effective seals. In this way, the cost of producing thefilter may be reduced. Additionally, the snap-lock features of the innerfilter 362 and the outer filter 360 allow for a simplified filterassembly process that does not require additional gaskets or glue, andprevents the disengagement of the inner filter 362 from the outer filter360.

The terminology used herein is intended to describe particularembodiments and is not intended to be limiting. The terms “a,” “an,” and“the” include the plural forms as well, unless clearly indicatedotherwise. The terms “comprises” and/or “comprising,” when used herein,specify the presence of the stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, and/or components.

With regard to the preceding description, it is to be understood thatchanges may be made in detail, especially in matters of the constructionmaterials employed and the shape, size, and arrangement of parts withoutdeparting from the scope of the present disclosure. The word“embodiment” as used herein may, but does not necessarily, refer to thesame embodiment. The embodiments described herein are exemplary only.Other and further embodiments may be devised without departing from thebasic scope thereof, with the true scope and spirit of the disclosurebeing indicated by the claims that follow.

What is claimed:
 1. A fuel water separator filter, comprising: an outerfilter with a bottom endplate; and an inner filter at least partiallydisposed within and secured to the outer filter, the outer filter andthe inner filter combined providing a plurality of water separatinglayers, wherein the inner filter comprises: a first sealing regionconfigured to produce a seal between the inner filter and a filterhousing, a second sealing region configured to produce a seal betweenthe inner filter and a standpipe structure of the filter housing, and athird sealing region configured to produce a seal between the innerfilter and an endplate of an outer filter.
 2. The fuel water separatorfilter of claim 1, wherein the inner filter further comprises asnap-lock attachment configured to engage the outer filter.
 3. The fuelwater separator filter of claim 1, wherein the inner filter furthercomprises an anti-backoff portion configured to engage the outer filterand prevent the inner filter from disengaging the outer filter.
 4. Thefuel water separator filter of claim 1, wherein the inner filter furthercomprises openings configured to allow water removed from a fuel flowthrough the fuel water separator filter to drain to a water sump of thefilter housing.
 5. A fuel water separator filter, comprising: an outerfilter; and an inner filter at least partially disposed within andsecured to the outer filter, the outer filter and the inner filtercombined providing a plurality of water separating layers, wherein theinner filter includes an endplate configured to seal an end of the outerfilter.
 6. The fuel water separator filter of claim 5, wherein the innerfilter is formed integrally as a single unitary structure with theendplate.
 7. The fuel water separator filter of claim 5, wherein theinner filter further comprises: a first sealing region configured toproduce a seal between the inner filter and a standpipe structure of afilter housing; and a second sealing region configured to produce a sealbetween the inner filter and the filter housing.
 8. The fuel waterseparator filter of claim 5, wherein the inner filter further comprisesopenings configured to allow water removed from a fuel flow through thefuel water separator filter to drain to a water sump of a filterhousing.
 9. A fuel water separator filter, comprising: an outer filter;and an inner filter at least partially disposed within and secured tothe outer filter, wherein: the inner filter further comprises a framestructure, a snap-lock structure, and a top cover; the outer filter andthe inner filter combined provide a plurality of water separatinglayers; and the snap-lock structure is configured to engage the outerfilter.
 10. The fuel water separator filter of claim 9, wherein thesnap-lock structure and the frame structure are formed as separatecomponents.
 11. The fuel water separator filter of claim 9, wherein thesnap-lock structure and the frame structure are integrally formed assingle unitary structure.
 12. The fuel water separator filter of claim9, wherein the frame structure and the top cover are formed as separatecomponents.
 13. The fuel water separator filter of claim 9, wherein thesnap-lock structure comprises a sealing region configured to produce aseal between the inner filter and a standpipe structure of a filterhousing.
 14. The fuel water separator filter of claim 9, wherein thesnap-lock structure comprises snap-lock legs configured to engage a baseportion.
 15. The fuel water separator filter of claim 14, wherein thesnap-lock legs form openings configured to allow water removed from afuel flow through the fuel water separator filter to drain to a watersump of a filter housing.
 16. The fuel water separator filter of claim14, wherein the snap-lock legs are configured to self-center the innerfilter in the outer filter.
 17. The fuel water separator filter of claim14, wherein the base portion is integrally formed as a single unitarystructure with an endplate of the outer filter.
 18. The fuel waterseparator filter of claim 14, wherein the base portion is formed as aseparate piece that snap-lock engages with an endplate of the outerfilter.
 19. The fuel water separator filter of claim 14, wherein thebase portion comprises a sealing region configured to produce a sealbetween the base portion and a filter housing.
 20. A fuel waterseparator system, comprising: a filter housing comprising: a standpipestructure, and an isolated water sump; and a fuel water separator filterdisposed in the filter housing, the fuel water separator filtercomprising: an outer filter, and an inner filter at least partiallydisposed within and secured to the outer filter, the outer filter andthe inner filter combined providing a plurality of water separatinglayers, wherein the inner filter comprises: a first sealing regionconfigured to produce a seal between the inner filter and the standpipestructure, and openings configured to allow water separated from a fuelflow through the fuel water separator filter to flow to the isolatedwater sump.
 21. The fuel water separator system of claim 20, furthercomprising a fuel pump in fluid communication with the fuel waterseparator filter, wherein the fuel water separator filter is disposed ona low pressure side of the fuel pump.
 22. The fuel water separatorsystem of claim 20, wherein the filter housing further comprises a wallconfigured to separate an interior space of the filter housing into theisolated water sump and a filter chamber configured to receive the fuelwater separator filter.
 23. The fuel water separator system of claim 20,wherein the inner filter further comprises: a second sealing regionconfigured to produce a seal between the inner filter and a portion ofthe filter housing other than the standpipe structure, and a thirdsealing region configured to produce a seal between the inner filter andthe second endplate.
 24. The fuel water separator system of claim 20,wherein the inner filter further comprises an endplate.
 25. The fuelwater separator system of claim 20, wherein the inner filter furthercomprises: a frame structure, a snap-lock structure configured to engagethe outer filter, and a top cover.
 26. A fuel water separator filter,comprising: an outer filter; and an inner filter at least partiallydisposed within and secured to the outer filter, the outer filter andthe inner filter combined providing a plurality of water separatinglayers, wherein the inner filter comprises means for securing the innerfilter to the outer filter and means for producing a seal between theinner filter and a standpipe structure of a filter housing.
 27. The fuelwater separator filter of claim 26, further comprising: means forpreventing the inner filter from disengaging the outer filter.
 28. Thefuel water separator filter of claim 26, further comprising: means forallowing water separated from a fuel flow through the fuel waterseparator filter to an isolated water sump of the filter housing.